JSFiddle - React, Tailwind, and code Playground

HTML

<textarea id="textarea"></textarea>
<br />
<input type="submit" value="Cut string" onClick="cutTheString()" />
<input type="text" id="string1"></input>
<input type="text" id="string2"></input>
<input type="text" id="string3"></input>

JavaScript

function cutTheString()
{
  var str = document.getElementById('textarea').value;
  var arrayOfStrings = str.split('|');
  for(var i = 0; i < arrayOfStrings.length; i++) {
     document.getElementById("string" + (i+1)).value = arrayOfStrings[i];
  }
}